File: clean.sh
   1 #!/bin/sh
   2 
   3 # The MIT License (MIT)
   4 #
   5 # Copyright (c) 2026 pacman64
   6 #
   7 # Permission is hereby granted, free of charge, to any person obtaining a copy
   8 # of this software and associated documentation files (the "Software"), to deal
   9 # in the Software without restriction, including without limitation the rights
  10 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11 # copies of the Software, and to permit persons to whom the Software is
  12 # furnished to do so, subject to the following conditions:
  13 #
  14 # The above copyright notice and this permission notice shall be included in
  15 # all copies or substantial portions of the Software.
  16 #
  17 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23 # SOFTWARE.
  24 
  25 
  26 # clean [options...] [command] [args...]
  27 #
  28 #
  29 # CLEAN the screen, after running the command given. When its standard output
  30 # is piped, no cleaning happens, and this script becomes a passthru.
  31 #
  32 # This tool doesn't clear the screen, but rather uses the alternative screen
  33 # buffer, so the original content of the terminal is restored when done.
  34 #
  35 # The options are, available both in single and double-dash versions
  36 #
  37 #   -h, -help       show this help message
  38 #   -p [msg]        wait/prompt for the enter key before quitting
  39 #   -pause          wait/prompt for the enter key before quitting
  40 #   -v, -verbose    show styled banner of command run
  41 #   -w, -when       also show when command was run, if in verbose mode
  42 
  43 
  44 when=0
  45 pause=0
  46 prompt=''
  47 verbose=0
  48 
  49 while [ $# -gt 0 ]; do
  50     case "$1" in
  51         -h|--h|-help|--help)
  52             awk '/^# +clean /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
  53             exit 0
  54         ;;
  55 
  56         -p|--p)
  57             if [ $# -lt 2 ]; then
  58                 printf "%s: expected prompt message after %s option\n" \
  59                     "$0" "$1" >&2
  60                 exit 1
  61             fi
  62             pause=1
  63             if [ "$2" = '--' ]; then
  64                 shift 2; break
  65             fi
  66             prompt="$2"; shift 2; continue
  67         ;;
  68 
  69         -pause|--pause) pause=1; shift; continue ;;
  70 
  71         -v|--v|-verbose|--verbose) verbose=1; shift; continue ;;
  72 
  73         -w|--w|-when|--when) when=1; shift; continue ;;
  74 
  75         --) shift; break ;;
  76 
  77         -*)
  78             printf "%s: unsupported option %s\n" "$0" "$1" >&2
  79             exit 1
  80         ;;
  81     esac
  82 
  83     break
  84 done
  85 
  86 if [ $# -eq 0 ]; then
  87     awk '/^# +clean /, /^$/ { gsub(/^# ?/, ""); print }' "$0" >&2
  88     exit 1
  89 fi
  90 
  91 title=''
  92 if [ "${verbose}" -eq 1 ]; then
  93     if [ "${when}" -eq 1 ]; then
  94         # d="$(date)"
  95         # d="$(date +'%Y-%m-%d %H:%M:%S %a %b %d')"
  96         d="$(date +'%Y-%m-%d %H:%M:%S')"
  97         title="$(printf "%s        %s" "${d}"  "$*")"
  98     else
  99         title="$(printf "%s" "$*")"
 100     fi
 101 fi
 102 
 103 prompt="${prompt:-Press the Enter key to continue...}"
 104 
 105 # if stdout is being piped, avoid alternate-screening
 106 if [ -p /dev/stdout ]; then
 107     [ "${verbose}" -eq 1 ] && printf "\033[7m%-80s\033[0m\n" "${title}"
 108 
 109     if [ "${pause}" -eq 0 ]; then
 110         exec "$@"
 111     fi
 112 
 113     "$@"
 114     res=$?
 115     printf "\n%s" "${prompt}"
 116     read -r ignored
 117     exit "${res}"
 118 fi
 119 
 120 # restore previous screen contents when sent a SIGINT signal, which usually
 121 # happens by pressing Ctrl+C
 122 trap '
 123     tput -T xterm rmcup 2> /dev/null || printf "\033[?1049l\033[23;0;0t"
 124     exit 130
 125 ' INT
 126 
 127 tput -T xterm smcup 2> /dev/null || printf "\033[?1049h\033[22;0;0t"
 128 printf "\033[H" # move cursor to the top-left corner
 129 
 130 [ "${verbose}" -eq 1 ] && printf "\033[7m%-80s\033[0m\n" "${title}"
 131 
 132 "$@"
 133 res=$?
 134 
 135 if [ "${pause}" -eq 1 ]; then
 136     printf "\n%s" "${prompt}"
 137     read -r ignored
 138 fi
 139 
 140 tput -T xterm rmcup 2> /dev/null || printf "\033[?1049l\033[23;0;0t"
 141 
 142 exit "${res}"